I agree with the basic idea of this pull-request. But I don't like the directory name coreonly which role is not clear from the directory name.

Thanks for your comment.
🤔 Hmmm, is src/libmruby_core/ acceptable?

src/nogem maybe?

MRB_NO_GEMS may be defined in libmruby.a builds.

# build configuration
MRuby::Build.new do
  toolchain
end

Also, I don't think libmruby_core.a is very good about nogem since it doesn't include mruby/mrblib.

However, if you think src/nogem is OK, I will update this patch accordingly.

I still feel unclear about what the term libmruby_core_only_objs means and what it is used for. Please explain a little more. Japanese is fine.

すでに libmruby_core_objs がありますが、これは libmruby_objs の一部としても使われています。

libmruby_core_objs を別の名前に変更する場合は互換性の面で少し気になったため、( (libmruby_core + only) + objs) という名前で提案しました。